Safety guard for punch presses



Dec. 1 7, 1929.

E. P. JOHNSON SAFETY GUARD FOR PUNCH PRESSES Filed March 31, 1927 Patented Dec. 17, 1929 lllTED ST hit-0,412

SAFETY GUARD FOR EUNCH Application filed March 31, 1927. Serial No. 1%,930.

It is well known that punch press operators are apt to have their fingers or hands smashed or injured while operating the press, these accidents occurring either from failure a to remove the hands in time during the normal operation of the press or frequently on account of some defect or breakage which would cause the press to operate in an abnormal manner, as by repeating a stroke instead 10 of coming to a stop. Accidents of this nature are numerous and often costly. The present invention relates to a device or apparatus for guarding the press and preventing the accidental injury to the operator.

The objects of the present invention are to provide a guard which will be simple in corn struction, which may be readily applied to various types of presses, and which will be particularly efficient and durable in operav tion; to provide a guard of this kind which may be adjusted for difierent presses or different conditions; to provide a guard which will be positive in action and which will safeguard the operator and tend to fully prevent any injury to his hands.

These objects are obtained by means of the device shown in the accompanying drawings, in which Figure 1 is a front view of a press showing my guard applied thereto;

Figure 2 is a sectional detail taken on the line 2-2 of Figure 1; and

Figure 3 is a sectional detail taken on the line 3 of Figure 1.

The punch press 4 shown in these drawings may be of any ordinary or preferred con struction, such press being illustrative of the different types of presses to which my improved guard may be applied. The plunger 5 is reciprocated by means of the driving apparatus and carries the upper punch or die member, and it is this part which is the dangerous part of the press as it or the push or die carried thereby is apt to strike the operators hand or jam it against the lower die or block. In order to prevent such injury, I provide a combined stationary and movable guard. An angular bracket 6 is provided with a slot 7 for receiving the usual gib screw 8 for attaching the upper or fixed portion of the guard to the press. The bracket (5 has an outwardly projecting leg 9 with a bolt 10 which passes therethrough and engages with a slot 11 in the upper leg 12 of a horizontally adjustable bracket 13. The

outer or vertical portion of this bracket has a bolt 1 which engages with a slot 15 in a horizontally adjustable bar 16 which projects inwardly to the center press. The inner end of this bar has bolt 17 which engages with a slot 18 in a vertically adjustable bar 19. These pa are arranged to provide all necesadj ments for a pivot pin 20 which carries a swinging curved arm 21. lhis arm in some instances may be used directly as the guard member for moving the operators hand or hands away from the throat or operative parts of the nachine, but I prefer to use an adjustable finger 22 which is connected to the arm 21 by means of a clamp 23. The arm 21 is actuated at the proper time by means of an angle bracket or operating member 24 which is secured to the plunger or reciprocating member 5 by means of the screw 25, this screw being one commonly forming a part of the press. The angle bracket 2a is connected with the arm 21 by means of a pivoted block 26 which is pivotally connected to the angle bracket, as shown in F igure 3, and

wvhich has a hole 27 for receiving the arm 21 which is adapted to slide therethrough.

In addition to the movable guard, I provide a fixed guard 28 comprising a rod bent to form a loop 29 at the upper end thereof for receiving a bolt 30 by means of which it is adjustably secured to the bar 16. The lower end of this rod may be bent or fashioned in any desirable manner, as in the form of a double loop so that it will cifectively serve as a guard element.

hen the plunger is in raised position, the angle bracket 2% through the connection 26 swings the pendulum arm 21 to the left, as shown in Figure 1, so as to leave a free opening to the throat or operative part of the press and there is nothing to hinder the action of the operator in feeding the press in the usual manner. lVhen the plunger descends, the arm 21 isswung downwardly and to the right to the position shown in dotted lines in Figure 1 so that it sweeps across in front of the dies. If the operator has failed to remove his hand or hands from beneath the plunger when it is making its downward stroke, this movement of the guard will push or move the hand out of the danger zone and thereby prevent any possible injury. It will also be noted that if material is being fed to the press, for instance with the right hand in front of the plunger and the left hand guiding or moving the material from the left of the machine, the stationary guide member 28 will prevent the left hand from moving into the danger Zone or where it will be apt to be struck by the plunger or other moving parts. It will therefore be seen that by means of this relatively simple mechanism the operator is fully guarded and there is little or no chance for accidental injury. it will also be noted that the various adjustments provide means whereby the device may be readily applied to different types of presses and the guard members may also be conveniently adjusted with respect to any workpieces which are to be placed in the machine to be operated upon.

My improved guard may also be modified if necessary to adapt it for different conditions or uses, and therefore I do not wish to limit myself to the exact form or arrangement herein shown and described, but what I claim and desire to. secure by Letters Patent 1s:

1. A guard of the character set forth, comprising a bracket adapted to be secured to a press, a second bracket adjustably mounted on the first named bracket, a bar adjustably mounted on said second named bracket, a second bar adjustably secured to the first named bar, a curved arm pivotally mounted on the second named bar, a finger adjustably secured to said arm, an angle bracket adapted to be secured to the press plunger, a bearing pivoted to the angle bracket and having a hole for receiving the arm for swinging the same, and a stationary guard adjustably secured to the first named bar.

2. A device of the character set forth, comprising a bracket having a slot in one leg thereof, a bolt through the other leg of the bracket, a second bracket having a slot in one leg thereof for receiving said bolt, a bolt through the other leg of the second named bracket, a bar engaging with said second named bracket and having a slot for receiving said bolt, a bolt in said slot, a bent rod adjustably engaging with said last named bolt, another bolt through the bar, a second bar having a slot for receiving the last named bolt, a curved rod pivotally secured to the last named bar, a bracket adapted to be secured to a movable part of the press, and a pivotal and sliding connection between the lastnamed bracket and the rod whereby the rod will be swung when the bracket is moved.

3. A double safety guard for presses or the like comprising a support which is vertically and horizontally adjustable, a round rod having a curved bearing portion and pivoted at one end to said support, a round finger adjustably secured to said rod to form an extension thereof, a bracket adapted to be secured to the plunger of the press, a block pivoted on said bracket and having a hole for receiving the curved portion of said rod, and a longitudinally and transversely adjustable stationary guard positioned at the side of the movable guard at its point of rest, the arrangement being such that the stationary guard is adapted to prevent the hands of the operator from following the movable guard as it moves forwardly.

4. A safety guard for punch presses comprising a support adapted to be adjustably mounted on the press, an arm pivotally mounted on said support and having a curved portion adjacent to the pivot, an operating member adapted to be secured to a movable portion of the press, a block pivotally mounted on said operating member and having a hole therethrough for receiving the curved portion of the arm, the arrangement being such that when the movable portion of the press is actuated it will cause the block to move along the arm and swing the arm across in front of the press.

EDlvARD P. JOHNSON. 

